Ring groove cleaning tool



Feb. 8, 1966 c. w. LORSON 3,233,268

RING GROOVE CLEANING TOOL Filed June 9, 1964 Cfemeni' W Larson INVENTOR.

BY mm United States Patent 3,233,268 RING GROOVE CLEANING TOOL Clement W. Larson, 1069 Melo Drive, Beaverton, Oreg. Filed June 9, 1964, Ser. No. 373,729 Claims. (Cl. 15-104.01)

This invention relates to tools for cleaning the ring grooves in the pistons of internal combustion engines, and particularly to such a tool which enables the cleaning of ring grooves without disconnecting the piston and connecting rod from the crank shaft of an engine of the air cooled type.

In internal combustion engines of the air cooled type, such as that utilized in the C-orvair automobile, the pistons may be exposed by removing the cylinder heads from the block, whereupon the pistons project freely outward from the block. Howeventhe cylinder head securing studs project from the block in such close proximity to the pistons as to prevent the use of ring groove cleaning tools provided heretofore. Thus, although the ring grooves are exposed, it has been required heretofore to remove the oil pan and disconnect the connecting rods from the crank shaft so as to remove the pistons from the block in order to eifect cleaning off the ring grooves. It is because of this requirement for major disassembly of the engine that the desirable procedure of cleaning the ring grooves has been restricted primarily to those instances in which major overhaul of the engine is required.

Accordingly, it is the principal object of the present in vention to provide a ring groove cleaning tool which enables the cleaning of ring grooves on pistons which are exposed outwardly from the cylinder block, without removal from the engine.

Another important object of this invention is the provision of a ring groove cleaning tool in which the cleaner elements are adjustable radially and longitudinally relative to the axis of the piston.

A further important object of the present invention is the provision of a ring groove cleaning tool which is of simplified construction for economical manufacture and which is operable with speed, facility and precision.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawing in which:

FIG. 1 is a fragmentary view in side elevation of a conventional air cooled internal combustion engine with a cylinder head thereof removed to expose a piston projecting from the engine block, the piston having mounted thereon a ring groove cleaning tool embodying thefeatures of the present invention;

FIG. 2 is a plan view of the ring groove cleaning tool as viewed from the top in FIG. 1;

FIG. 3 is a sectional view taken along the line '3-3 in FIG. 1; and

FIG. 4 is a fragmentary sectional view taken along the line 44 in FIG. 2.

The conventional air cooled internal combustion engine illustrated in FIG. 1 includes a cylinder block 14) provided with a plurality of cylinder bores (not shown) in each of which a piston 12 is movable reciprocatively by means of a connecting rod 14 secured at its outer end to the piston and at its inner end to a crank shaft (not shown). Individual cylinder heads (not shown) are associated one with each cylinder block bore, and each head includes a bore registering with the corresponding bore in the block for movement of the piston therein. Each cylinder head is secured to the block by means of elongated studs 16 secured to the block and projecting outwardly therefrom at spaced positions about the cylinder block bore.

3,233,258 Patented Feb. 8, 1966 Thus, with the cylinder head removed from the block, as illustrated in FIG. 1, the head studs are positioned .closely adjacent the circumference of the exposed piston and project outwardly beyond the latter.

The ring groove cleaning tool of the present invention accommodates cleaning of the piston ring grooves 18 of the illustrated type of engine, without removing the pist-on from its confined position within the projecting studs. To this end the tool includes a hollow base member providing a cylindrical side wall 20 open at its inner end for receiving the outer portion of a piston freely therethrough. The outer end of the cylindrical wall is at least partially closed by means which supports a driving head. In the embodiment illustrated, this supporting means is an imperforate cover plate 22 formed integral with the cylindrical side wall. A drive stud 24 is secured to this cover plate at the axial center of the cylindrical wall, and projects outwardly therefrom and terminates in a noncircular drive head 26. This head is adapted to releasably receive a driving implement by which to rotate the cleaning tool. In the embodiment illustrated the hexagonal head is adapted to receive a socket type wrench, Well known in the art. It will be apparent that the noncircular male type driving head illustrated may be replaced by a non-circular socket.

Alternatively, the cover plate supporting the drive head 26 may take the form of a plurality of circumferentially spaced spokes radiating inwardly from the cylindrical wall to a central hub to which the drive stud 24 is secured.

The cylindrical wall is provided with an arcuate slot 30 intermediate its inner and outer ends. A cutter member is mounted freely in this slot for substantially radial movement relative thereto. In the embodiment illustrated, the cutter member includes a cutter head 32 having a plurality of inwardly projecting cutter teeth 34 dimensioned and spaced apart to conform to the width and spacing of the ring grooves 18 in the piston. The cutter head is secured, as by means of the rivets 36, to one end of an elongated arm'38.

In the embodiment illustrated, the 'arm 38 is mounted adjacent its opposite end on a pivot pin, illustrated as a headless screw 40. The screw is secured releasably to a web 42 which traverses the slot adjacent the leading end of the latter, i.e. the end leading in the direction of rotation of the tool as indicated by the arrow in FIG. 3. The opening 44 in the arm for the screw 40 is made somewhat larger than the latter. In this manner the arm may effectively pivot on the screw, about an axis substantially parallel to the axis of the cylindrical wall 20, to move the cutter head in the radial direction of the cylindrical wall. Additionally, the arm may pivot about the axis of the screw 40, substantially normal to the axis of the side wall 20, to facilitate aligning the cutter teeth 34 with the ring grooves 18 in the piston. The end of the arm extending in the leading direction from the screw 49 is offset to form an outwardly facing notch 46 to freely receive therein the stabilizing web 48 which traverses the slot a spaced distance from and leading the mounting web 42. Removal of the arm and cutter head assembly from the base member thus may be effected simply by rotating it counterclockwise (FIG. 3) about the web 42 and withdrawing the offset portion from between the webs 42 and 48.

Alternatively, the arm 38 may be made of spring steel, or other similarly resilient material, in which case the screw 40 may be provided with an enlarged head and tightened sufficiently to hold the arm rather firmly, but permitting the latter to rotate slightly about the axis of the screw, to permit alignment of the cutting teeth 34 with the ring grooves 18. In this instance the web 48 and associated leading notch portion of the arm may be omitted, if desired.

Means is provided for adjusting the cutting teeth 34 to various cutting depths radially inward of the cylindrical wall 29. In the embodiment illustrated, this means is provided by the arcuate adjusting member 50 which is positioned to traverse an arcuate portion of the slot in an area overlying the cutter head 32 and a portion of the supporting arm 38. The adjusting member is supported on the cylindrical wall for limited arcuate movement relative thereto, by means of a pair of offset lugs 52 which project inwardly from the inner surface of the adjusting member, adjacent the inner and outer edges thereof, to provide outwardly facing arcuate grooves 54. These grooves freely receive therein the arcuate guide flanges 56 which project inwardly from the inner and outer edges defining the slot 30. The guide flanges terminate at their trailing ends a distance forwardly of the trailing end of the slot greater than the length of the lugs 52. In this manner the adjusting member may be detached from the cylindrical wall by sliding it in the trailing direction sufliciently to disengage the lugs from the guide flanges.

Normally, however, the extent of movement of the adjusting member in the trailing direction is limited by its abutment against a stop member which, in the embodiment illustrated, comprises a bar 58 releasably secured in a groove 69 in the cylindrical wall by means of the screw 62. The bar projects into the slot 39 suificiently to intercept one of the guide lugs 52 on the adjusting member, and it is positioned adjacent the trailing end of the associated guide flange 56. Thus, in order to remove the adjusting member it is necessary first to remove the stop member, as will be apparent.

The inner surface of the adjusting member 50 is disposed for sliding engagement with the outer surface of the cutter head 32, which outer surface is contoured to provide an outwardly projecting cam surface 64 which projects progressively outward with respect to the cylinder wall in the trailing direction of rotation of the tool. Thus, as the adjusting member is moved along the guide flanges 56 in said trailing direction, the cutter head is moved progressively inward. In this manner the cutter teeth 34 are adjustable radially with respect to the cylinder wall and hence to varying depths within the ring grooves 18 of the piston.

The operation of the cleaning tool described hereinbefore is as follows: With the cylinder head of the engine removed to expose the piston 12, as in FIG. 1, the adjusting member 50 is rotated in the leading direction of rotation of the tool sufiiciently that the cutting tips of the cutter teeth 34 are retracted outwardly substantially to the inner surface of the cylinder wall 20. The latter thus may be slipped freely over the exposed end of the piston, with the latter in abutment with the cover plate 22 and the cutter teeth thus approximately aligned with the ring grooves in the piston. The adjusting member then is moved along the guide flanges 56 in the trailing direction of rotation of the tool, thereby bearing slidably against the cam surface 64 of the cutter head 32 and forcing the cutter teeth radially inward into contact with the carbon deposits contained within the ring grooves.

In the event the cutter teeth are misaligned slightly from the ring grooves 18, the arm 38 may be pivoted about the axis of the screw 4% to elfect proper alignment.

A turning tool, such as a socket and ratchet wrench, then is connected to the drive head 26 and the tool rotated in the cutting direction of rotation. After one revolution of the tool, with consequent removal of a portion of the carbon deposit in the ring grooves, the adjusting member 50 is moved still further in the trailing direction to force the cutter teeth further inward into the ring grooves, and the tool once again rotated through one revolution. This step Wise adjustment or" the cutter teeth inwardly into the ring grooves is repeated until all of the carbon deposits have been removed from the ring grooves. Thereafter, the adjusting member is retracted, in the leading direction of rotation of the tool, allowing the cutter teeth to retract from the ring grooves and permit removal of the tool from the piston.

From the foregoing it will be apparent that the present invention affords means for cleaning the ring grooves of pistons with speed, facility and precision, and is of particular value in cleaning the ring grooves of pistons of air cooled engines, simply by removing the cylinder heads.

It will be apparent to those skilled in the art that various changes in the details of construction described hereinbefore may be made without departing from the spirit of this invention and the scope of the appended claims.

Having now described my invention and the manner in which it may be used, what I claim as new and desire to secure by Letters Patent is:

1. A piston ring groove cleaning tool, comprising (a) a hollow base member including a cylindrical side wall and an outer end wall, the side wall being open at its inner end to receive a piston freely therein,

(b) a drive member on the outer end wall for rotating the base member,

(c) the side wall having an arcuate slot therein,

((1) a cutter member mounted on the side wall in the slot for substantially radial movement relative to the side Wall,

(e) at least one cutter on the cutter member projecting inwardly of the side Wall for reception in a ring groove of a piston, and

(f) a cutter adjusting member mounted on the side wall for engagement with the cutter member and movable relative to the side wall to effect said movement of the cutter member.

2. The cleaning tool of claim 1 wherein the cutter memher is mounted on the side wall for pivotal movement on an axis substantially parallel to the axis of said side wall.

3. The cleaning tool of claim 1 wherein the cutter head is mounted on the side wall for pivotal movement on an axis substantially parallel to the axis of said side wall and also on an axis substantially normal to the axis of said side wall.

4. The cleaning tool of claim 1 wherein the adjusting member is mounted on the side wall for arcuate movement relative thereto, and the cutter member includes a cam portion slidably engageable by the adjusting member.

5. The cleaning tool of claim 4 including a stop member on the side Wall disposed to intercept the path of movement of the adjusting member to limit said movement in the direction effecting inward movement of the cutter head.

References Cited by the Examiner UNITED STATES PATENTS CHARLES A. WILLMUTH, Primary Examiner. 

1. A PISTON RING GROOVE CLEANING TOOL, COMPRISING (A) A HOLLOW BASE MEMBER INCLUDING A CYLINDRICAL SIDE WALL AND AN OUTER END WALL, THE SIDE WALL BEING OPEN AT ITS INNER END TO RECEIVE A PISTON FREELY THEREIN, (B) A DRIVE MEMBER ON THE OUTER END WALL FOR ROTATING THE BASE MEMBER, (C) THE SIDE WALL HAVING AN ARCUATE SLOT THEREIN, (D) A CUTTER MEMBER MOUNTED ON THE SIDE WALL IN THE SLOT FOR SUBSTANTIALLY RADIAL MOVEMENT RELATIVE TO THE SIDE WALL, (E) AT LEAST ONE CUTTER ON THE CUTTER MEMBER PROJECTING INWARDLY OF THE SIDE WALL OF RECEPTION IN A RING GROOVE OF A PISTON, AND (F) A CUTTER ADJUSTING MEMBER MOUNTED ON THE SIDE WALL FOR ENGAGEMENT WITH THE CUTTER MEMBER AND MOVABLE RELATIVE TO THE SIDE WALL TO EFFECT SAID MOVEMENT OF THE CUTTER MEMBER. 